The present invention relates to storage system, more particularly to a method or apparatus for managing a storage subsystem or device.
In recent years, a plurality of information apparatus are combined in a complicated manner into a complex configuration for whose management there has been proposed a means such as a large-scale network requiring a skilled network administrator. In particular, the process to increase the capacity of a storage apparatus (e.g., a disk-array apparatus) is frequently performed. The configuration of a storage system has also been increasing in complexity in that a plurality of storage apparatuses are linked to a network for data transfer via the network. The capacity of a storage apparatus can be increased by employing large-size storage disks to operate concurrently in the storage apparatus. In this case, it is necessary to manage the storage disks in a uniform manner.
Instead of implementing a storage apparatus as a single large magnetic-disk apparatus, the storage apparatus can employ a number (e.g., more than 1000) of inexpensive small magnetic disks provided in a redundant configuration to operate concurrently. In such a configuration, data can be stored in two different disks for back-up purposes. Thus, the data input/output performance resulting from concurrent operations a device having a plurality of magnetic disks and data reliability can be improved.
Then, in response to a demand for increase of storage capacity of a disk-array apparatus and enhancement of reliability, the number of magnetic disk storages in the disk-array apparatus is increased. Accordingly, the configuration of the disk-array apparatus becomes complicated due to, among others, the fact that the internal configuration of a disk-array control apparatus becomes redundant. In addition, the number of logical volumes and other entities set in the disk-array apparatus can reach as high as 8000 or more. As a result, loads of physical and logical apparatus configurations' operation management and maintenance management increase significantly.
In addition, for the purpose of increasing the management efficiency, integrated remote maintenance management and the like are executed on a plurality of disk-array apparatus installed in different locations. A variety of set control parameters of a utility (a management application) implemented as a service processor (SVP) or the like provided in the disk-array is set. That is, a person in charge of storage-system management (system administrator) views a performance display screen to obtain information on load distribution, on the basis of which the control parameters are set and configuration information is changed.
In an operation to set the control parameters as described above, a system administrator of a storage subsystem (disk-array apparatus) generally can not determine the state of the entire apparatus by merely looking at one screen of the management application since mutual correlations exist in many instances. For this reason, a configuration design carried out on a desk while collecting many pieces of information from scattered sources is desirable.
With the configuration of a disk-array control apparatus keeping up with a disk-control apparatus having a large size and a large storage capacity, in a work carried out by a storage system administrator to execute volume control and set a variety of parameters for the purpose of configuring and improving the performance of the system based on load distribution, operations become complicated and difficult to determine consequences of such operations/implementations.
In addition, in a disk-array apparatus or system having a complicated configuration designed for a large size and a large storage capacity, e.g., an enterprise system, the current system's parameters and configuration are not easy to modify quickly. In one embodiment, one disk-array apparatus includes 1,000 or over more storage disks, providing over 8,000 logical volumes. There is also a danger that a system failure may result from performing certain reconfigurations or operations.
It is to be noted that, there is a personal computer or the like that allows video and audio data to be reproduced or playback from a compact disk serving as an external storage device in real time. With such a personal computer, however, the operations can be carried out to control the playback, e.g. controlling audio or video reproduction. The system's parameters and configuration, e.g., creating logical volumes, associating a particular parity group with one or more logical volumes, or other acts that effects where data are stored within a storage device, are not easy to modify immediately in real time. Such a personal computer thus provides a technique essentially different from the technique in which it is feared that an unexpected problem such as a system failure is raised in some setting operations (i.e., involving system configuration or reconfiguration). That is to say, in an operation to read out data from a compact disk, the original data itself generally is not lost due to a change in configuration.